Dorion, JF 2019, 'Corroded rock support issues: implementation of an investigation and rehabilitation program', in J Hadjigeorgiou & M Hudyma (eds), Ground Support 2019: Proceedings of the Ninth International Symposium on Ground Support in Mining and Underground Construction, Australian Centre for Geomechanics, Perth, pp. 401-414, https://doi.org/10.36487/ACG_rep/1925_27_Dorion
(https://papers.acg.uwa.edu.au/p/1925_27_Dorion/)
Abstract: Raglan Mine site includes four underground mines extracting nickel (Katinniq, Kikialik, Qakimajurq and Mine 2). It is located at the extreme north of the province of Quebec. Due to freezing weather and the permafrost environment, the use of brine is mandatory. This brine is composed of about 10% calcium chloride and is corrosive to rock support systems. With mines extending deeper below the permafrost, brine flows more freely in the rock mass. The corrosion of support systems and the resulting loss of capacity can be a major safety and economic concern. Centred on rock support issues, this paper presents the mitigation measures implemented at Raglan Mine to ensure safety and the investigation program methodology to quantify and prioritise rehabilitation needs of long-term excavations. In corrosive environments, the selection and design of rock support should take the susceptibility of such systems to corrosion into consideration.

Keywords: corrosion, brine, capacity, fall of ground, rehabilitation, inflatable bolt, pull test